The University of Iowa, backed by the Board of Regents, is continuing to refuse court-ordered payment to one of its contractors for work on its new $392.7 million Children’s Hospital, accusing the contractor of extortion and game-playing and indicating patients could be unsafe in the towering facility.UI President Bruce Harreld on Thursday told regents that although it’s willing to pay Merit Construction, of Cedar Rapids, what it owes, UI won’t pay Modern Piping, Inc., also of Cedar Rapids, until it gives the university “as-built” documents that spell out in detail how the hospital was built and where electrical wiring, valves, pipes and other infrastructure lies behind the hospital walls.Harreld last week promised to pay Modern Piping the remaining nearly $18 million of a $21.5 million award.